The continuing miniaturization of semiconductor integrated circuits has forced many conventional structures to change and has required the accompanying need to improve the processes used to create the new structures. A conventional MOS (metal oxide semiconductor) transistor gate structure for larger feature sizes includes a deposited tungsten nitride barrier layer and a tungsten via layer. Sputtering is the generally preferred method of depositing the WN barrier layer and the W via layer. However, tungsten resistivity increases with reduced film thickness, resulting in a decrease in usefulness for future node DRAM in bitline applications.
Therefore, there is a need in the art for films and methods to deposit films with lower bitline resistivity and insensitivity to oxidation.